Handhole closure



Feb. 27, 1968 J. E. BEARDON HANDHOLE CLOSURE Filed Dec. 21, 1965 INVENTOR,

FIG 3 JAMEs E, REARDON M f m,

United States Patent 3,370,742 HANDHOLE CLOSURE James E. Reardon, Chattanooga, Tenn, assignor to Combustion Engineering, Inc., Windsor, Conn, a corporation of Deiaware Filed Dec. 21, 19:35, Ser. No. 515,352 Claims. (Cl. 226-25) ABSTRACT OF THE DISCLOSURE A handhole closure of the self insertingweldable type where a skirt extends into the opening and is welded to the wall thereof at the skirt extremity. Mechanism is provided to effect a temporary seal without welding whereby after the temporary sealing the closure may be easily removed for inspection purposes,

This invention relates to handhole closures and particularly to such closures as employed with high pressure-high temperature boilers.

It is the present practice in these boilers to provide self inserting-weldable handhole closures for numerous openings in the headers and vessels or drums that form a part of the boiler. The openings that are sealed by these closures are circular and the enclosure includes a plate which is insertable through the opening from the outside of the header or vessel and which engages the rear face of the header or vessel wall and overlies the opening. The closure plate includes a skirt or cylindrical lip which extends into the opening adjacent the opening wall with this skirt or lip being seal welded to this wall. These closures have proved very satisfactory.

During the initial stages of putting a boiler into operation, or in other words getting it on the line, several operations that are conducted such as, hydrostatic testing, boil-out, and acid washing after each of which or after all of which it is necessary to remove the handhole covers to inspect the internal surfaces of the headers and vessels. Heretofore this has necessitated removing the seal Welds and replacing these welds when the cover is put back in place. This removing of the welds is a reiatively time consuming and expensive task, and may result in damage to either the closure plate or the header.

The present invention is directed to an improved handhole closure which eliminates the need for seal welding the closure plate in order to carry out the aforementioned operations and which utilizes a temporary seal in cooperation with the closure plate for sealing the openings during these initial operations.

Accordingly, it is an object of this invention to provide an improved handhole closure for use with high pressure high temperature boilers.

A further object of the invention is to provide a temporary seal assembly which forms part of the closure and is effective to provide a temporary seal of the opening with which the closure is employed.

Other features and advantages will be apparent from the specification and claims and from the accompanying drawings which will illustrate an embodiment of the invention which will be described by way of example and in which:

FIG. 1 is a longitudinal sectional view illustrating the closure with the temporary seal means that forms a part thereof and with the closure being shown mounted in an opening in the wall of a header or vessel;

FIG. 2 is a transverse sectional view of the closure plate per se and is taken generally along line 22 of Patented Feb. 27, 1968 FIG. 4 is an elevational view of the closure plate per se and is taken generally from line 4-4 of FIG. 2; and

FIG. 5 is an end view of the closure plate taken gen erally from line 5-5 of FIG. 4.

Referring now to the drawings, the closure as illus trated in FIG. 1 includes a closure plate 10 which is referred to as a self inserting-weldable closure plate. This plate is self inserting since it is of a construction that it can be inserted through the circular opening 12 in the wall 14 of the header or vessel. This is accomplished by making this plate elongated as shown in FIG. 4, so that its width is slightly smaller than the diameter of the opening 12 while its length is substantially greater than this diameter. Thus, the plate may be inserted from the outer face 16 of the header wall through the opening 12 and then be positioned as shown in FIG. 1 where it extends across the opening and overlies the rear face of this wall. As disclosed, it is received in a suitable recess 18 provided in this rear face. The closure plate includes a cylindrical lip or skirt 20 which extends into the opening 12 when the plate is in position as shown in FIG. 1. This lip is necessary in order to accommodate the expansion and contraction that takes place during the seal welding operation as well as during operation of the boiler with which the handhole closure is utilized.

After the closure plate 10 is inserted through the opening 12 the stud 22 is threaded into the recess 24 provided in this plate. This stud carries yoke 26 and nut 28 positioned outwardly of this yoke such that threading the nut onto the stud will cause the extremities of the yoke to bear against the outer face 16 of the wall and thus draw the plate 10 tightly into position.

A temporary seal for use during the initial operations carried out when putting a boiler into operation is obtained by use of a circular seal plate or disc 3% which is also received on the stud 22 and which is forced toward and into engagement with the extremity of skirt 20 by means of the nut 32. This seal plate is provided with bleed opening 34 so as to prevent air being trapped in the recess 35 formed intermediate lip 20 and the boss or raised portion 37 within which the recess 24 is formed.

Intermediate the seal plate 30 and the extremity of lip 20 there is provided a flexible toroidal seal 38. The seal plate is chamfered as shown so that as the seal plate is urged toward the extremity of skirt 20 the toroidal seal is forced against the skirt and outwardly into engagement with the wall of the opening 12. The seal thus produced is effective and satisfactory with relation to the initial operations in putting a boiler into service such as hydrostatic testing, boil-out and acid Washing. After these operations are complete it is desired that the closure plate be seal welded into place. To accomplish this plate 30, seal member 38 and nut 32 are removed. This may be accomplished by removing the stud 22 and then removing nut 32 from the stud or by removing the yoke 26 and its operating nut 20 and then removing plate 30, seal 38 and nut 32. After these elements have been removed closure plate 10 is again secured in place by the stud 22, nut 28 and yoke 26. The closure plate is then tack welded into place with yoke 26 permitting access to the end of skirt 20 for this purpose. The yoke and stud are then removed after which complete seal welding is effective with the weld being made in the location of the seal 38 disclosed in FIG. 1.

It will thus be appreciated that with the improved handhole closure of this invention an effective temporary seal is provided in a simple and economic manner whereby after each of the aforementioned initial operations the closure may be readily removed for inspection of the interior of the header and vessel, and yet after these initial inspections a positive seal welded construction is provided.

It is to be understood that the invention is not limited to the specific embodiment herein illustrated and described, but may be used in other ways without departure from its spirit and that various changes can be made which would come within the scope of the invention which is limited only by the appended claims.

I claim:

1. A closure for circular openings in walls of headers and the like comprising in combination an elongated closure plate adapted to be inserted from the front face of the wall through the opening and to occupy a closing portion in overlying relation with the rear face, said plate having a skirt extending into said opening in proximity to the wall of the opening when in said closing position such that the distal end of said skirt may be welded to said wall, a removable stud extending outwardly from said closure, a means adjustably mounted on the stud operative to retain the closure in place in the opening, said means permitting access to said skirt for welding and means operative to provide a temporary seal including means removably mounted on the stud intermediate the first mentioned means and the closure plate and adjustable into juxtaposition to said skirt, a seal ring intermediate said second means and the distal end of said skirt and forced into sealing engagement with the wall of opening by adjustment of said second means toward said skirt.

2. The closure of claim 1 wherein the first mentioned means comprises a yoke received on said stud and adapt- 4 ed to bridge the opening and engage the 'front'face of the wall and a nut threadedl received on the stud outwardly of said yoke.

3. The closure of claim 1 wherein said second means comprises a disc received on said stud and having a diameter slightly smaller than that of the opening, and a nut threaded on said stud outwardly of said disc for adjusting the same with relation to said closure plate.

4. The closure of claim 1 wherein said means operative to retain the closure in place includes a yoke received on the stud and adapted to bridge the opening and en gage the front face of the wall and a nut threadedly received on the stud outwardly of said yoke, and wherein the means for providing a temporary seal includes a disc received on the stud and having a diameter slightly smaller than that of the opening, and a nut threaded on said stud outwardly of said disc for adjusting the same with relation to said closure plate.

5. The closure of claim 4 wherein said disc is provided with a chamfer directed toward said closure plate and effective to urge said seal ring into engagement with the wall of the opening.

References Cited UNITED STATES PATENTS 1,659,301 2/1928 Nelis et a1. 22025 THERON E. CONDON, Primary Examiner.

GEORGE T. HALL, Examiner. 

